Pump housing with an interior space for accommodating a pump rotor

Abstract

Pump housing (9, 9', 9'', 9''', 9'''', 39, 39', 39'', 39''') with an interior space for accommodating a pump rotor (10, 10', 10'', 10'''), which can be converted from a radially compressed state into a radially expanded state and has a housing skin (43, 43') running around its circumference and at least one reinforcing element (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 45, 46, 47, 48, 49), wherein in the fully expanded state of the pump housing (9, 9', 9'', 9''', 9'''', 39, 39', 39'', 39'''), the housing skin (43, 43') circumferential direction by the expansion of the reinforcing element / reinforcing elements (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 45, 46, 47, 48, 49) and wherein at least one stretch-resistant element (37, 43, 50) running circumferentially is provided, which in the expanded state is stretched by less than 5% in the circumferential direction compared to the force-free state and which prevents further expansion of the pump housing (9, 9', 9'', 9''', 9'''',39, 39', 39'', 39'''), wherein the stretch-resistant element (37, 43, 50) is arranged in an axial section of the pump housing (9, 9', 9'', 9''', 9'''', 39, 39', 39'', 39''') which accommodates the pump rotor (10, 10', 10'', 10''').

Description

The invention is in the field of mechanical engineering and is used in particular in medical technology. It relates to pumps equipped with pump rotors and having a pump housing, the interior of which accommodates the pump rotor. Especially in medical technology, but fundamentally also in other fields of application of technology, pumps are known which are radially compressible in that both the rotor and the pump housing are deformable in order to reduce the diameter and which can be expanded again after transport to the place of use in order to set the dimensions required for an optimized function. Furthermore, especially in medical technology, such pumps are known which can be compressed to such an extent that they can be introduced into the body of a patient via a blood vessel and can be expanded there in order to assist or independently ensure blood transport via the operation of the pump.In order to ensure reliable compressibility and expandability, a multiplicity of technical tasks have to be achieved.For example, U.S. Pat. No. 7,393,181 B2 describes a compressible pump rotor in which delivery blades are arranged in rows on a hub and can be folded onto the latter.U.S. Pat. No. 7,841,976 B2 discloses a pump rotor which can be inserted into the expandable part of a cannula in order to be operated there after the corresponding cannula part has expanded. For this purpose, the rotor is driven via a shaft which runs through the cannula. The pump thus formed can be advanced through a blood vessel into a heart chamber and operated there.U.S. Pat. No. 7,927,068 B2 also describes a pump having a rotor which has a hub and delivery blades which can be folded on and off. During operation, the conveying blades are pressed in rotation by the fluid counterpressure which is produced into the position which is suitable for the pumping operation.DE 100 59 714 C1 discloses an intravascular pump with a compressible and expandable housing which has a mesh mesh. This housing can accommodate a rotor and be introduced into a blood vessel by means of an introducer sheath. Further prior art of a related type is described in the publication WO 03 / 103 745 A2.The cited prior art is generally concerned with the problems of radially compressing a pump having a rotor and a pump housing sufficiently to be insertable into a blood vessel of a patient, for example, and expandable after the insertion. Later, the respective pump should also be compressible again in order to be able to be explanted. In the compression and expansion process, both the rotor and the housing are usually correspondingly deformed. A particular challenge in this case is the requirement to minimize the pump gap, i.e. the interspace between the rotor, more precisely the radially outer ends of the conveying elements, and the inner housing wall of the pump housing during operation, in order to optimize the pump operation, especially the efficiency and the compression of the pump. The pump gap must be kept very small and in particular as constant as possible in order to prevent overflow at the radially outer ends of delivery elements of a rotor, on the other hand the delivery elements or other elements of the rotor must as far as possible not contact the inner wall of the pump housing in order to generate no unnecessary friction losses or abrasion at the high usual rotational speeds of more than 10000 revolutions per minute.Against the background of the prior art, the present invention is therefore based on the object of creating a pump housing and a pump of the type mentioned at the beginning which / s permit the most precise and reproducible possible adjustment of the pump gap.The object is achieved according to the invention with the features of claim 1.The pump housing accordingly has a housing skin and at least one reinforcing element, wherein in the fully expanded state of the housing the housing skin is stretched in the circumferential direction by the expansion of the reinforcing element and wherein at least one stretch-resistant element running circumferentially in the circumferential direction is provided, which in the expanded state is stretched in the circumferential direction by less than 5%, in particular less than 1%, compared to the force-free state and which limits a further expansion of the pump housing.The housing skin can consist of a readily deformable flexible, in particular flexurally limp, plastic and contain a polymer, for example. The housing skin can be simply arranged around the reinforcing element or connected to it by conventional joining techniques such as adhesive bonding or welding. The reinforcing element can also be integrated into the housing skin by casting.Usually, the reinforcing element is constructed and arranged in such a way that it radially supports the housing skin from the inner side. This is also possible in the case of an integration, for example a casting, of the reinforcing element into the housing skin.Upon expansion of the pump housing from a compressed state, the reinforcement member or group of reinforcement members deforms and stresses the housing skin by exerting a radially outward force thereon. The hydrodynamic and in particular hemodynamic properties of the pump housing are improved in particular when the housing skin is tensioned, in particular tensioned free of folds, and the inner wall of the pump housing, which delimits the interior space for receiving the pump rotor, is as smooth as possible.However, this should not result in variable extension forces being generated by the forces acting on the housing skin depending on the magnitude of the forces acting through the reinforcement elements, so that the dimensions of the interior of the housing vary. For this purpose, the invention provides a circumferential stretch-proof element which is not substantially stretchable due to the radially outward forces of the reinforcing element / elements. The stretch-proof element is arranged in the axial section of the pump housing, which receives the pump rotor. The stretch-proof element can also cover the entire axial length of the pump rotor.The stretch-proof element can also be a flexurally slack film which is, for example, substantially stretch-proof than the housing skin and can surround the latter radially.The stretch-proof element can also merely surround the reinforcing elements, itself be radially surrounded by the housing skin or replace the housing skin.The pump housing advantageously has at least one axial section in which the interior space is substantially cylindrically shaped. This cylindrically shaped axial interior region can accommodate the pump rotor, for example.Such a cylindrical shape is also intended to include approximately circular cylindrical shapes which are formed as polygonal prisms or polyhedrons, which are each inscribed in a circular cylinder and which are formed by the support of the housing skin by braces. The individual boundary surfaces of which the shape is made can be diamonds, for example.The pump housing or its interior can extend axially more or less far beyond the length of the pump rotor or the axial section provided for receiving the pump rotor, for example at least 2 cm, in particular at least 5 cm, further in particular at least 8 cm. The region of the pump housing that extends beyond the length of the axial section provided for receiving the pump rotor can be located distally, as seen from the pump rotor, i.e. towards the end of the pump housing at which the latter has its intake side with an intake opening. At the proximal end of the pump housing, an ejection opening for the fluid to be delivered is provided. However, the rotor can also protrude, at least partially, beyond the structure enclosed by a housing skin.The intake opening of the pump housing can be, for example, an end opening which is advantageously covered by an intake cage. The suction cage can have, for example, the shape of a spherical cap or, in the form of a balloon, can also initially provide an extension beyond the diameter of the pump housing, which extension is closed off towards the distal end by a cap or also a tip provided with a pigtail. The suction cage can be formed by continuous reinforcing elements of the pump housing.The pump housing can be cylindrically shaped up to its intake end and advantageously have a funnel-shaped widening at the intake end, from which the reinforcement elements emerge and form a balloon-like widened intake cage.On the discharge side or on the discharge-side end, the pump housing advantageously likewise has an end-face opening. Here, reinforcing elements can likewise emerge from the wall of the pump housing and lead to the central axis of symmetry of the pump housing, where they hold and center a catheter which runs coaxially with the pump housing with a smaller diameter than the pump housing and can, for example, accommodate a drive shaft for a pump rotor.The shape and size and the pretreatment of the reinforcing element / elements are advantageously selected such that the elastic forces of the reinforcing element / elements exceeding the actual radial expansion of the housing are so large in the expanded state of the housing that the radially outwardly directed excess forces are greater than 1 N, preferably 4 N. This means that even a radial force of the reinforcing elements reduced by the excess forces would still lead to a full expansion of the housing.This ensures that the housing is also not deformable, in particular cannot be compressed with respect to the diameter of the interior space, by a certain limited radial pressure from the outside (at most of the same magnitude as the excess forces). For compression of the pump housing, forces are necessary which at least exceed the forces of the reinforcing elements acting radially from the inside.In this way, it is ensured, in particular when the pump housing is in the aortic valve, that, when the valve is closed, the pump housing is not compressed and, as a result, the rotor is clamped in or braked by contact with the pump housing. Such contact would lead on the one hand to loss of the pump output, on the other hand also to the generation of abrasion and hemolysis, i.e. to damage of blood by acting shearing and grinding forces.The reinforcing element / elements can / can be, for example, elastically compressible struts made of a metal or a plastic, which are released for the expansion of the pump housing and elastically deform. A reinforcing element can also be formed, for example, as an annularly encircling element, for example as an open circular ring, which runs around the circumference of the pump housing and can be deformed as a whole between a spirally wound compressed state and an expanded state in which it is expanded to form a circular ring or a winding of enlarged diameter.It is also conceivable for the reinforcing element / elements to form a framework or arch which expands with respect to one another by pivoting individual elements. When forming such a framework or a arch, it can also be provided that they latch in a self-stabilized position in the expanded state.An advantageous embodiment of the invention provides that a framework or arch formed by the reinforcing element / elements in the expanded state of the housing resists radially inwardly directed forces of at least 1 N, preferably 4 N, without falling in.If the radially inwardly directed forces exceed this measure clearly, the arch or the frame yields, so that the pump housing can reduce its outer dimensions by compression and expand again after the inwardly directed forces are eliminated. The breakdown of the arch or scaffold can be reversible or irreversible.A further advantageous embodiment of the invention provides that the stretch-proof element is formed by a flexurally slack film, in particular by the housing skin.It can also be provided that the stretch-proof element is formed by a ring which runs circumferentially in the circumferential direction of the housing and surrounds the reinforcing element at least in sections. In particular, the stretch-proof element can surround the reinforcing element / elements in the region in which the pump rotor is accommodated.Advantageously, it can also be provided that the stretch-proof element is arranged on the radially outer side of the housing skin.To stabilize the stretch-proof element, in particular also the entire housing skin, it can advantageously be provided that the stretch-proof element has stretch-proof fibers, in particular glass fibers or carbon fibers, running in the circumferential direction. Other fibers or reinforcing elements are also conceivable for improving the yield strength.A particular embodiment of the reinforcing elements provides that they form a two-dimensional planar grid which is bent into the shape of a tube. The individual lattice elements are advantageously easily displaceable and / or pivotable relative to one another or else elastically deformable or bendable, so that deformation of the tubular structure is easily possible. The reinforcing elements can, for example, run around in sawtooth or meandering fashion in the circumferential direction of the pump housing.It can also be advantageously provided that a plurality of mutually pivotable reinforcing elements together form the shape of a tube in a first pivoting state and are radially compressed with respect to the tube shape in a second pivoting state. For this purpose, the reinforcing elements can be connected to one another at individual points, for example, and form joints, wherein the joint function can be realized by hinge-like devices, but also by elastic deformation.It can also be advantageously provided that the housing interior tapers, in particular conically, in the axial direction. This opens up the possibility of axially displacing the rotor to be introduced in the housing interior to such an extent that the housing gap, i.e. the intermediate space between the inner wall of the housing interior and the radially outermost ends of the rotor, in particular the conveying elements of the rotor, is optimized, for example minimized. The cone angle of the housing interior can thereby advantageously be between 0.5° and 5°, in particular between 0.5° and 2°.Advantageously, the outer contour of the pump rotor can also taper in the same sense as the housing interior, further advantageously with substantially the same taper angle. During operation of the rotor, the latter can then be displaced axially in the housing interior until the optimum pumping capacity is achieved. This can be determined, for example, by a flow measurement and / or in conjunction with a power measurement of the drive motor of the pump rotor. For example, the rotor can be moved until a distinct deceleration occurs, which corresponds to a contact reception of the rotor with the inner wall of the housing interior, and the rotor can then be moved back again by a defined axial distance and fixed in this axial position.The housing interior can, however, also have a slightly convex (spherical) or even concave shape. This is advantageous in particular if the rotor has different outer contours due to the deformation in the flow field at different operating states (e.g. rotational speeds). Depending on the basic shape of the rotor, a housing shape is then required which meets the respective requirements of all operating states.Regardless of whether a conical rotor or a rotor of cylindrical contour and a housing interior in conical or strictly cylindrical form are used, the pump gap should be between 0.01 mm and 1 mm, in particular between 0.01 mm and 0.3 mm, more advantageously between 0.03 mm and 0.15 mm. Here, the pump gap denotes the minimum distance between a radially outermost end of a part of the rotor and the inner wall of the housing interior, which occurs during the rotation of the rotor. In any case, it should advantageously be ensured that the rotor does not touch the pump housing during normal operation.In order to achieve an optimized compressibility and expandability of the pump housing, it can advantageously be provided that the reinforcing element / elements consist / consist of a superelastic material, in particular a superelastic alloy, further in particular nitinol. Such materials are very highly compressible without any concern and can also be designed as memory materials, in particular memory alloys, which assume a previously selected shape under certain physical conditions, for example when a certain temperature change or a target temperature occurs.Apart from a pump housing of the type described above, the invention also relates to a blood pump having a corresponding pump housing and having a rotor.The rotor can consist, for example, of a plastic, in particular a polyurethane, and advantageously also of a foam. It has one or more conveying elements which convey a liquid in the radial and / or axial direction with respect to the axis of rotation. The conveying elements can be designed as airfoils or as a single blade that passes through, wherein the single airfoil or a series of airfoils revolves helically about a central hub.Two helically encircling conveying blades can also be provided. The buckets may be cantilevered without a hub, or may be attached to or integrally formed with a central hub. Advantageously, the hub and the conveying elements can consist of the same material.The conveying elements can be designed such that they can be folded onto the hub for compression and can be folded off for expansion. In particular, in the force-free and stationary state of the rotor, the conveying elements assume a central position which corresponds neither to the compressed position nor to the expanded position. To assume the compressed position, a radial pressure is exerted from the outside on the conveying elements in order to place them tightly on a hub. The radial pressure can be applied, for example, by compression of the housing surrounding the rotor.If the radial pressure is reduced, the conveying elements are aligned a certain distance in the radial direction. A further raising can be effected by the fluid counter pressure at the beginning of the rotation of the rotor in the fluid to be conveyed.The delivery blades are typically designed such that during operation they are erected at the maximum in the radial direction at an optimized rotational speed, in particular at the maximum rotational speed of the pump, and thus exert the greatest possible delivery effect on the fluid. In this state of maximum erection, the dimensions of the interior of the pump housing and of the rotor must be matched to one another in such a way that no contact takes place between the two.It can also be provided that the individual conveying elements are deformed beyond the state of maximum radial raising by the fluid counter-pressure in such a way that they are radially compressed again a certain distance by the fluid pressure.In the pump housing, axially spaced apart from the rotor, in particular in the pump interior in which the rotor is located, a flow control element, in particular a valve, is advantageously also arranged, which prevents the return flow of the pumped fluid even in the idle state of the rotor. The flow control element controls the flow which passes through the rotor, that is to say, for example, the flow through the annular space between a rotor hub and the inner wall of the pump housing.The control element / valve is located outside the hub, for example axially spaced apart from the rotor hub. It has, for example, one or more pivotable flaps which can be moved by the flow itself by being opened by the flow in the case of a flow in the conveying direction and automatically closed by the return flow in the case of a flow counter to the conveying direction. The flaps themselves may be resiliently deformable in themselves and the flow control means, like the rotor, is radially compressible and expandable.If a plurality of individual conveying elements are provided along a hub, these can advantageously be arranged and aligned in such a way that they overall form the contour of a helical conveying blade. The individual conveying elements can then be folded and expanded individually onto the hub.The rotor, in particular the hub, but advantageously both the hub and the conveying elements, advantageously consists of a polyurethane, for example also of a foamed polyurethane, a thermoplastic elastomer, a rubber or a superelastic material, in particular a superelastic polymer.Apart from a pump housing and a blood pump with such a pump housing and a rotor, the invention also relates to a blood pump device with a pump housing, a rotor and a catheter adjoining one end of the pump housing. The catheter can be part of a manipulation device, for example, which allows the pump housing and the rotor to be at least partially inserted through a blood vessel of a patient into a heart chamber.The catheter has in particular a longitudinally traversing lumen, in which a drive shaft for the rotor of the pump is arranged. However, a motor can also be arranged in the immediate vicinity of the pump housing for driving the rotor.The catheter can advantageously be connected directly to the pump housing, wherein radial openings for the fluid to be delivered can be provided either at the end of the pump housing and / or at the beginning or in the course of the catheter. The catheter advantageously has a substantially smaller diameter than the interior of the pump housing and is fastened to the end of the pump housing. It is advantageously connected coaxially and concentrically to the pump housing. The connection can be formed, for example, by means of the reinforcing elements of the pump housing, which project axially beyond the pump housing and can be bent centrally radially inward in order to be connected there to the catheter. Thus, the extensions of the reinforcement elements / struts of the pump housing can hold and center the catheter.The invention is shown in a drawing on the basis of an exemplary embodiment and described below. This shows FIG. 1 shows a schematic representation of a blood pump introduced into a heart chamber via a blood vessel, FIG. 2 shows a blood pump in a heart chamber in longitudinal section, FIG. 3 shows a blood pump in a side view, FIG. 4 shows a part of a pump housing with reinforcing elements, FIG. 5 is a side view of a pump housing with reinforcing elements, FIG. 6 shows reinforcing elements for a pump housing in expanded form, FIG. 7 shows the reinforcing elements from FIG. 6 in compressed form, FIG. 8 shows a longitudinal section through a part of a pump housing with a rotor, wherein the pump interior is designed conically, FIG. 9 shows a part of a longitudinal section of a pump housing with a rotor, wherein the housing interior is of cylindrical design, FIG. 10 shows a schematic longitudinal section through a blood pump, FIG. 11 is a longitudinal section through a part of a pump housing with a reinforcing element, FIG. 12 is a longitudinal section through a pump housing with circular ring-shaped reinforcing elements, FIG. 13 is a longitudinal section through a part of a blood pump with a pump housing and an element and reinforcing elements which are resistant to stretching, FIG. 14 shows a longitudinal section through a part of a blood pump with a valve downstream of the rotor, FIG. 15 shows an arrangement similar to FIG. 14 with a valve upstream of the rotor, FIG. 16 shows an arrangement in which a rotor ejects a fluid through a cage via a valve, FIG. 17 shows an embodiment of a valve in two positions, and FIG. 18 shows a further embodiment of a valve in two positions.FIG. 1 schematically shows a blood vessel 1 of a human body which is connected to a heart chamber 3 via a heart valve 2 and into which a catheter 4 is introduced via a lock 5. The catheter 4 has a channel (lumen) in its interior, via which a drive shaft 6 leads from an external drive motor 7 to a heart pump 8 introduced into the heart chamber 3. The heart pump 8 can be introduced into the blood vessel, for example, in the known Seldinger technique, and advanced through the latter as far as the heart chamber.The heart pump 8 has in its interior a rotor which can be driven by means of the drive shaft 6 at a few thousand, typically between 10000 and 50000 revolutions per minute and conveys blood in the axial direction. The rotor is surrounded by a pump housing which has a distal suction opening via which the blood in the heart chamber 3 can be sucked in.Blood pumps of this type are used either temporarily or permanently to replace or support natural cardiac function. It is especially when using such a heart pump in a supporting manner that it is advantageous if the natural activity of the heart remains unaffected, so that the heart itself also contributes to the pumping function by the heart valve. For this purpose, the heart can either perform pumping work supporting through the pump or can convey blood past it through the heart valve parallel to the heart pump.In FIG. 2 an embodiment of a heart pump is shown with an approximately cylindrical pump housing 9 in expanded form, in which a rotor 10 is located. The rotor 10 has, for example, a conveying element in the form of a conveying blade which runs helically on a hub 11. The space which the rotor assumes during its rotation is cylindrical and is adapted as exactly as possible to the housing interior of the housing 9.The pump housing 9 has at its distal end a suction cage 12 which is formed by some struts which simultaneously form reinforcing elements of the pump housing 9, are embedded in the material of the pump housing and project axially beyond the latter in the distal direction.At the distal end of the suction cage 12 there is arranged an traumatic tip 13 which in the example has the form of a ball 14 which ensures that the pump does not damage vessel walls or heart walls when it is pushed into the blood vessel and the heart chamber and that the suction end with the suction opening 12 of the pump housing 9 does not suck fast on a vessel wall when blood is being conveyed.In an axial region 15 of the pump housing, a foil-like outflow jacket 16 is connected to the pump housing in a fluid-tight manner. The outflow jacket 16 consists of a flexible, flexurally slack, very thin film which covers the outflow openings 17 of the pump housing 9, which are arranged on the jacket side, and extends beyond the latter a distance further in the proximal direction of the pump, i.e. in the direction of the lock 5. The heart valve, schematically indicated by the reference numeral 18, presses the outflow jacket 16 against the continuation of the pump housing 9 and thus closes the heart chamber with respect to the blood vessel 1. This is the case in particular in the phase when the residual function of the heart, which is assisted by the pump, causes an additional increase in pressure in the inflow region of the pump. This ensures that the blood flow from the heart chamber into the blood vessel is modulated with the temporal structure of the natural heart action.FIG. 3 shows a side view of a further blood pump with a pump housing 9', in which lattice-like reinforcing elements 20 in the form of wire-like struts are shown. The reinforcing elements 20 are continued at the distal end of the pump housing 9' in free struts 21, 22, 23 to form an intake cage which allows the inflow of blood, indicated by the arrows 30, 31.The suction cage 21, 22, 23 also has a so-called pigtail 31 at its distal end, which is intended to prevent the suction cage from being suctioned firmly against a vessel wall.At the proximal end, the pump housing 9' has an ejection opening 32 at the end face, from which the blood, indicated by the arrow 33, can be ejected into a blood vessel.The proximal continuation of the pump housing 9' is formed by a catheter 4' which has in its interior a cavity for receiving a drive shaft for the pump.The pump housing 9' is constructed with the reinforcement elements 20 in such a way that it can be easily radially compressed together with the suction cage.The reinforcing elements 20 can be integrated, for example, into a flexible film which forms the housing skin and is non-stretchable, so that after the expansion of the struts 20 it prevents an expansion of the pump housing 9' beyond a firmly defined state.FIG. 4 shows a side view of a cylindrical section of a pump housing with inserted reinforcing elements 24, 25 which are designed to be circumferential in the circumferential direction, meandering in the case of the reinforcing element 24 and sawtooth-shaped in the case of the reinforcing element 25. This shape permits simple radial expansion and compression of the housing. Reinforcing elements running transversely thereto can additionally be provided.FIG. 5 schematically shows a reinforcing element 26 which is integrated as a helical spring into a housing 9". This reinforcing element 26 too is compressible in a simple form.FIG. 6 shows a plurality of circular rings 27, 28 which are formed overall into a tube and in this way can support a pump housing, not shown.The rings can be rotated relative to each other about an axis lying in the plane of the drawing, so that they all lie in the same plane, as shown in FIG. 7. In this position, the reinforcing elements 27, 28 are very strongly compressed in a radial direction (perpendicular to the plane of the drawing), while they have unchanged dimensions in the radial direction perpendicular thereto.FIG. 8 shows a longitudinal section of a part of a pump housing with a rotor, wherein the pump housing 9"' has a housing interior which tapers conically in the direction of the arrow 34. The cone angle is exaggerated in the figure for better visibility. Cone angles of the order of magnitude of fewer degrees, in particular between 0.5° and 5°, further in particular less than 2°, are suitable. The outer contour 35 of the rotor 10', which is illustrated by dashed lines, is likewise designed to be conical, and in fact advantageously with the same cone angle as the interior of the housing 9'''.If the rotor 10', for example with the aid of the drive shaft, not shown, is pulled into the narrowing region of the cone of the pump housing 9''', an ever tighter fit results between the outer contour of the rotor 10' and the inner wall of the housing 9'''. The rotor can be pulled until the optimum pump gap is reached.In contrast to FIG. 8, FIG. 9 shows an ideally cylindrical pump housing 9"", having a likewise cylindrical interior space, in which a rotor 10" is arranged, which likewise has a cylindrical contour, indicated by the dashed line 36. This configuration is insensitive to axial displacements of the rotor 10" with respect to the housing 9"".Such a constellation can also be used independently of the idea of the main claim, namely the use of a stretch-proof element for limiting the radial expansion of a pump housing, generally in rotor pumps.FIG. 10 shows schematically the longitudinal section of a pump housing 39 with a rotor 10'''. The outer contour of the rotor 10''' is cylindrical and is located in a cylindrical section of the housing 39. reinforcing elements 29 are integrated into the housing wall of the housing 39 by casting, which are responsible for the expansion of the pump and tension the housing skin. A stretch-proof element 37 in the form of an annular strip is shown, which radially surrounds the housing skin of the housing 39 and thus effectively limits the radial expansion of the pump housing 39. The reinforcing elements 29 are still tensioned so far even in the expanded state of the pump that they act upon a further expansion of the pump housing 39 with a certain excess force. This leads to a force acting radially from the outside on the pump housing 39 and not exceeding a magnitude between 1 and 25 N not leading to a radial compression of the housing 39.The stretch-proof element 37 can be configured, for example, as a high-strength plastic film, in particular also with reinforcing fibers running around in the circumferential direction, for example made of or with glass fiber or carbon fiber materials or also made of or with aramid fibers or nylon fibers.The heart valve of a heart into which the pump is introduced is indicated in FIG. 10 with the reference numeral 38. It is also shown that the pump housing 39 protrudes axially in the distal direction beyond the end 40 of the rotor 10"', shown by a dashed line. The pump is positioned in a heart chamber such that the rotor 10"' is outside the heart chamber in a blood vessel, while a portion of the housing 39 extends distally from the dashed line 40 into the heart chamber. The suction opening 41 is arranged in the heart chamber itself, which is covered by a suction cage 42.The length of the housing continuation of the housing 39 distal from the end 40 of the rotor to the suction opening 41 can be between a few millimeters and a few centimeters, for example between 0.5 and 10 cm, in particular between 0.5 and 5 cm or 0.5 and 2 cm.Fig. 11 illustrates another structure of the pump casing 39' in which a casing outer skin 43 is directly provided with circumferentially encircling reinforcing fibers 44 so that the casing skin 43 itself constitutes the stretch-proof member. Above the horizontal dashed line, a helical reinforcing element 45 is shown radially inside the housing skin 43, which may be formed by a spring steel spiral. However, the spiral can also be formed by a plastic and be cast into the housing skin, as shown below the dashed line.In FIG. 12 a pump housing 39" is shown, which consists of a material which is resistant to expansion on itself and surrounds the reinforcing elements 46, 47, 48, which are each individually designed as circular rings. The individual circular rings can be collapsed with a sufficient force for compressing the housing 39" or rotated in such a way that all circular rings lie one above the other in the cylinder axis of the housing 39" in the same plane.FIG. 13 shows a constellation with a pump housing 39''', wherein the outer skin 43' of the housing consists of an expandable membrane and the radially inner reinforcement struts 49, which form a braid and are still elastically compressed a certain distance even in the expanded state of the pump and act upon a further expansion of the housing, are held in tubular form by an expansion-resistant element 50. The stretch-proof element 50 is cylindrically shaped and sized so that when tensioned by the reinforcement elements 49, the housing skin 43' is also properly tensioned. The elastic excess forces of the reinforcing elements 49, which are designed as a wire mesh, are dimensioned such that a force acting radially from the outside on the housing 39''', if it does not exceed 3 N, does not lead to a deformation of the housing 39''' and to a reduction in the diameter of the housing interior.At its distal end 51, the housing skin 43' has a funnel-shaped widening 52, which facilitates the inflow of blood through the suction opening 53. At the same time, in the case that reinforcing elements extend in the housing skin 43' of the housing 39''', they can run out axially from the funnel-shaped widening 52 and form a balloon-like widened suction cage. The exemplary reinforcement elements integrated into the wall of the housing 39"' are denoted 54, 55.FIG. 14 shows a side view analogous to FIG. 3 of a further blood pump. Also shown is the rotor 10' and, proximally thereof, an additional valve 60 which prevents the blood from flowing back when the pump is at a standstill, and in this way replaces the valve function which, in FIG. 2, the outflow jacket 16 shown there, together with the heart valve 18. The valve is formed here by a plurality of flap-like, advantageously film-like sails which open under the flow pressure of the pump in the direction of the arrow 61 and close again when the pump is at a standstill. The sails can be formed integrally with the housing skin or fastened to the latter. During the compression of the pump, the sails are also placed against the wall of the housing, in order to ensure the diameter reduction in this region as well.FIG. 15 shows a blood pump analogous to FIG. 14, wherein the arrangement of rotor and valve is interchanged. This arrangement is advantageous in that the drive shaft of the rotor does not extend within the valve.FIG. 16 shows a blood pump analogous to FIG. 15, wherein the flow direction of the blood is reversed here. Such pumps, in which the blood flows from the proximal end of the housing, to which the catheter is attached, to the distal end of the housing, can be used, for example, advantageously for cardiac support in the right ventricle.FIG. 17 shows a longitudinal section, as is also FIG. 18, of a pump housing 9'. In FIG. 17, a rotor 10''' is also shown. In extension of the shaft 62, a stop body 63 is formed for the leaflets 64, 65 of a valve against which the leaflets abut in the case of a flow direction in the direction of the arrow 66. In a flow direction in the direction of the arrow 67, the sails, which are fastened to the housing inner wall, open the flow channel / the valve.FIG. 17 shows a stop body which narrows in the inflow direction.FIG. 18 shows a stop body which has a cone 68 in the inflow direction, but is formed flat on its outflow side.The constellation shown here can also be used, independently of the conditions of the main claim, generally in rotor pumps, in particular compressible rotor pumps.Aspects of the invention relate, inter alia: 1. blood pump having a pump housing which has a conically tapering housing interior and a rotor arranged therein, wherein the rotor is cylindrical in its contour or likewise tapers conically in its outer contour in the same sense as the interior of the housing, and wherein the cone angles of the outer contour and of the housing interior are approximately the same. 2. method for adjusting a blood pump according to the first aspect, wherein the rotor is displaced axially relative to the pump housing during rotational operation until it is ensured by determining the load of the drive motor of the pump that the rotor rotates in the pump housing without contact. 3. pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') with an interior for receiving a pump rotor (10, 10', 10", 10"'), which can be transferred from a radially compressed state into a radially expanded state, wherein at least one element for changing the flow resistance for a fluid flow passing through the interior, in particular a valve, is provided at axial distance from the rotor. 4. pump housing according to aspect 1, wherein the element, in particular the valve, is formed in the interior of the housing. 5. pump housing according to one of the preceding aspects, wherein the at least one element, in particular the valve, can be transferred from a radially compressed state to a radially expanded state. 6.Pump housing according to one of the preceding aspects, wherein the valve function is exerted in the expanded state. 7. pump housing according to one of the preceding aspects, wherein the element has at least one pivotable and / or deformable planar element, in particular in the form of a sail or a flap, which opens a flow duct under flow pressure in a first direction of flow and closes it when the pump is at a standstill or when the flow pressure is directed in the opposite direction. 8. pump housing according to one of the preceding aspects, wherein the element / elements is / are configured as a foil-like sail. 9. pump housing according to one of the preceding aspects, wherein at least one of the elements is fastened to the housing. 10. pump housing according to one of the preceding aspects, wherein the element / elements is / are formed integrally with the housing skin. 11.Pump housing according to one of the preceding aspects, wherein at least one of the elements can be placed against the inner side of the housing wall and can be pivoted away from the latter. 12.Pump housing according to one of the preceding aspects, wherein a fixed body is fastened in the interior of the housing, against which the element / elements strike in the closed state of the valve.

Claims

Pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') with an interior for receiving a pump rotor (10, 10', 10", 10"'), which can be transferred from a radially compressed state into a radially expanded state and has a housing skin (43, 43') running circumferentially in its circumferential direction and at least one reinforcing element (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 45, 46, 47, 48, 49), wherein in the fully expanded state of the pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"'), the housing skin (43, 43') is changed circumferentially by the expansion of the reinforcing element / elements (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 45, 46, 47, 48, 49 ) and wherein at least one stretch-resistant element (37, 43, 50) which extends circumferentially in the circumferential direction is provided and which, in the expanded state, is stretched less than 5% in the circumferential direction compared to the force-free state and which delimits a further expansion of the pump housing (9, 9', 9", 9"', 39, 39', 39", 39"'), wherein the stretch-resistant element (37, 43, 50) is arranged in an axial section of the pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') which accommodates the pump rotor (10, 10', 10", 10"').Pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') according to Claim 1, characterized in that the elastic forces of the reinforcing element / elements (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 45, 46, 47, 48, 49), which forces are directed towards a further radial expansion of the pump housing (9, 9', 9", 9"', 9"", 9"", 39, 39', 39", 39"'), in the expanded state of the pump housing (9, 9', 9", 9"", 39, 39', 39", 39"'), are so large that the radially outwardly directed forces are greater than 1 N.Pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') according to claim 1, characterised in that a frame or arch formed by the reinforcing element / elements (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 45, 46, 47, 48, 49) in the expanded state of the pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') resists radially inwardly directed forces of at least 1 N without falling in.Pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') according to one of the preceding claims, characterized in that the stretch-proof element (37, 43, 50) is formed by a flexurally slack film.Pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') according to Claim 1, characterized in that the stretch-proof element (37, 43, 50) is formed by a ring (37, 50) which runs in the circumferential direction of the pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') and surrounds the reinforcing element (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 45, 46, 47, 48, 49) at least in sections.Pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') according to claim 5, characterised in that the stretch-proof element (37) is arranged on the radially outer side of the housing skin (43).Pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') according to claim 5, characterised in that the stretch-proof element (50) is arranged on the radially inner side of the housing skin (43').Pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') according to claim 4, characterised in that the stretch-proof element (43) has stretch-proof fibres (44) running in the circumferential direction.Pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') according to one of the preceding claims, characterized in that the reinforcing elements (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 45, 46, 47, 48, 49) form a two-dimensional planar grid (20, 49) which is bent into the shape of a tube.Pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') according to one of the preceding claims, characterized in that a plurality of mutually pivotable reinforcing elements (27, 28) together form the shape of a tube in a first pivoting state and are radially compressed with respect to the tube shape in a second pivoting state.Pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') according to one of the preceding claims, characterized in that the inner wall (56) delimiting the housing interior tapers in the axial direction.Pump housing (9, 9', 9", 9"'. 9"", 39, 39', 39", 39"') according to any one of the preceding claims, characterized in that the reinforcement element / elements (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 45, 46, 47, 48, 49) is / are made of a superelastic material.Blood pump having a pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') according to one of the preceding claims and having a rotor (10, 10', 10", 10"').Blood pump device having a blood pump with a pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') according to claim 11 and with a catheter (4, 4') adjoining the blood pump.Fluid pump having a pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') according to one of Claims 1 to 12, wherein a rotor (10, 10', 10", 10"') is arranged in its interior, wherein the pump housing (9, 9', 9", 9"', 9"", 39, 39', 39", 39"') and the rotor (10, 10', 10", 10"') are designed to be radially compressible and expandable and wherein the rotor (10, 10', 10", 10"') has a concave and / or convex outer contour in at least one operating state in longitudinal section with respect to the space claimed during the rotation, and wherein the housing interior has an outer contour in longitudinal section corresponding to the outer contour of the rotor (10, 10', 10", 10"'), 10', 10'', 10''') have a contour adapted to the desired contour.

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